The teenager is the same age as Arsenal's first-year scholars and has already represented Northern Ireland at Under-17 level. The trial gives the Premier League club an opportunity to take a closer look at a player who has begun to gain experience in European youth competition.
O'Kane has featured twice for Cliftonville in the UEFA Youth League this season. Those appearances have added European experience to his development, alongside his involvement with Northern Ireland at age-group level.
The youngster is primarily a winger who operates on the left flank, but he is also capable of playing as a centre-forward. His ability to fill either role gives him flexibility in the attacking positions, although his main position is out wide.
Arsenal's assessment comes while O'Kane is still at the age of entering a first-year scholarship programme. The trial allows the club to assess his qualities directly, with his youth-team and international appearances providing some of the background to that evaluation, reports Jeorge Bird's Arsenal youth website.
For Cliftonville, the interest follows a season in which O'Kane has already featured in European youth fixtures. His two UEFA Youth League appearances have given him the chance to test himself against opposition from outside the domestic game.
For now, the confirmed information is that the 16-year-old has been with Arsenal this week. The trial is an opportunity for the club to look more closely at a Northern Ireland youth international who can play on the left wing or through the middle, but it should not be taken as confirmation that a move is imminent.